Vacuum sample collecting tube and method of collecting sample under vacuum

ABSTRACT

The present invention has for its object to provide a vacuum sampling tube which is capable of preventing a pretreating reagent accommodated in the vacuum sampling tube from entering the blood vessel and the like even in the event of a backflow of a specimen, such as blood, during vacuum sampling, such as vacuum blood collecting, and a vacuum sampling method.

TECHNICAL FIELD

The present invention relates to a vacuum sampling tube to be used inthe so-called vacuum sampling system for collection of specimens whichare aspiratable by utilizing a pressure difference between the insideand outside of the tube and a vacuum sampling method using said vacuumsampling tube. Above all else, the invention relates to a vacuum bloodcollecting tube for use in clinical examinations to be performed onblood specimens and a vacuum blood collecting method using said bloodcollecting tube.

BACKGROUND ART

While a typical vacuum blood collecting system is described in JapaneseKokai Publication Sho-62-227316, the fundamental construction of thesystem comprises:

1) as illustrated in FIG. 12, a vacuum blood collecting tube 30comprising a bottomed tubular casing 32 and a plug 31 having needlehole-sealable, gas-barrier properties as sealing the open end of saidcasing gas-tight to thereby keep a negative pressure within said casing;

2) as illustrated in FIG. 13, a vacuum blood collecting needle 40comprising a hollow needle of metal having needle tips 41 and 42 at bothends and a hub 43 provided with a male thread 44 on the plug-piercingside; and

3) as illustrated in FIG. 14, a holder for vacuum blood collection 50having a blood collecting needle-retaining aperture 51 provided with afemale thread engageable with the male thread of said hub 43 so thatsaid vacuum blood collecting tube 30 may be accepted into an internalcavity 52.

In blood collecting, the vacuum blood collecting needle 40 is threadedonto the blood collecting needle-retaining aperture 51 of the holder forvacuum blood collection 50. Then, the vacuum blood collecting tube 30 isinserted into said holder 50 and forced against the needle tip 42 of thevacuum blood collecting needle 40 to the extent that the plug 31 is notcompletely pierced through so as to temporarily seal the needle tip 42.This is done to prevent the blood from leaking out of the needle tip 42when the needle tip 41 is inserted into a blood vessel.

The person in charge of blood collection holds the whole of said bloodcollecting needle/said holder/said blood collecting tube assembly byhand in an incumbent position along the axis of the subject's bloodvessel and sticks the needle tip 41 on the blood vessel piercing sideinto the blood vessel. Then, as he or she advances said blood collectingtube 30 farther into said holder 50, the needle tip 42 on the plugpiercing side penetrates through the plug 31, with the result that theblood flows into said blood collecting tube due to the pressuredifference between the blood collecting tube side and the blood vesselside. Then, as the pressure difference is abolished, the blood inflowstops. Therefore, the whole assembly is withdrawn from the blood vesselto complete a blood collecting work.

Usually, depending on the object of an examination, said bloodcollecting tube involves a coagulation accelerator, an anticoagulant, adeproteinizing agent, a blood component stabilizer, and/or the like forthe pretreatment of a blood specimen in its inside. However, since thesedrugs denature the blood into a nonphysiological state different fromits state in vivo, the risk of these chemicals finding their way intothe subject's body in the event of a backflow by mistake during bloodcollecting has been pointed out.

For the prevention of such a backflow, Japanese Kokai PublicationSho-49-51784 and Japanese Kokai Publication Sho-50-12892 each proposes avacuum blood collecting needle provided with an elastic backflowprevention valve and Japanese Kokai Publication Sho-54-4191 proposes avacuum blood collecting tube plug which is provided with a similarelastic backflow prevention valve. The underlying principle of theseproposals is that as long as a pressure difference exists between theblood vessel side and the blood collecting tube side, the elastic valveis forced open by the hurriedly incoming blood flow, thus allowing bloodcollection, but as the pressure difference is abolished, the valvecloses to arrest the backflow. However, partly because of the inevitablycomplicated structures of the blood collecting needle and plug andpartly because said pressure difference is inherently small when theblood collecting size setting is small relative to the capacity of theblood collecting tube, the variation in the actual blood collecting sizebecomes remarkable when a variation occurs in the opening or closingforce of the elastic valve.

SUMMARY OF THE INVENTION

The present invention, developed to overcome the above-mentioneddisadvantages, has for its object to provide a vacuum sampling tubewhich is capable of preventing a pretreating reagent accommodated in thevacuum sampling tube from entering the blood vessel and the like even inthe event of a backflow of a specimen, such as blood, during vacuumsampling, such as vacuum blood collecting, and a vacuum sampling methodusing said vacuum sampling tube.

A vacuum sampling tube according to the first aspect of the presentinvention is a sampling vessel comprising

two tubular casings differing in size and each having a closed bottomand an opening at the other end as assembled together in the manner of anest of boxes,

wherein

1) the inner casing of the nest of boxes is sealed gas-tight at its openend by a gas-barrier, needle hole-sealable plug, whereby a negativepressure state is kept within said casing,

2) the outer casing of the nest of boxes is substantially not in contactwith an outer bottom surface of said inner casing of the nest of boxesbut is detachably associated at the open end of said outer casing withan outer peripheral surface of said inner casing in the vicinity of itsopen end in substantially liquid-tight relation, and

3) a specimen-pretreating reagent is accommodated in a space betweensaid inner casing and said outer casing.

A vacuum sampling tube according to the second aspect of the inventionis a sampling vessel comprising

a tubular casing having a closed bottom and an opening at the other endand

a cylinder having openings at both ends as assembled in said casing inthe manner of a nest of boxes,

wherein

1) the open top end of the inner cylinder of the nest of boxes is sealedgas-tight by a gas-barrier, needle hole-sealable plug,

2) said cylinder is detachably associated, respectively, with the openend of said tubular casing in the vicinity of its open top end insubstantially liquid-tight relation and with a plug means of saidtubular casing in the vicinity of cylinder's open bottom end insubstantially gas-tight relation,

3) a negative pressure state is kept with in said cylinder, and

4) a specimen-pretreating reagent is accommodated in a space betweensaid cylinder and said tubular casing.

A vacuum sampling tube according to the third aspect of the invention isa sampling vessel comprising

a tubular casing having a closed bottom and an opening at the other endand

a cylinder having openings at both ends as assembled in said casing inthe manner of a nest of boxes,

wherein

1) the open top end of the inner cylinder of the nest of boxes is sealedgas-tight by a gas-barrier, needle hole-sealable plug,

2) said cylinder is detachably associated, respectively, with the openend of said tubular casing in the vicinity of its open top end insubstantially liquid-tight relation and with a plug means of saidtubular casing in the vicinity of cylinder's open bottom end insubstantially gas-tight relation,

3) said open bottom end of the cylinder and said plug means of thetubular casing are provided with complementary notches and, by bringingsaid cylinder into sliding rotation about its axis, internal spaces ofsaid cylinder and said casing are reversibly brought into communicationor out of communication,

4) a negative pressure state is kept within said cylinder, and

5) a specimen-pretreating reagent is accommodated in a space betweenouter surface of said cylinder and inner surface of said casing.

A vacuum sampling tube according to the fourth aspect of the inventionis a sampling vessel comprising

a tubular casing having a closed bottom and an opening at the other endand

a cylinder having openings at both ends as assembled in said casing inthe manner of a nest of boxes,

wherein

1) the open top end of the inner cylinder of the nest of boxes is sealedgas-tight by a gas-barrier, needle hole-sealable plug while the openbottom end thereof is sealed gas-tight by a gas-barrier member which canbe broken through at least locally, whereby a negative pressure state iskept within said cylinder,

2) said cylinder is designed in such manner that its open bottom endfaces a plunger member disposed inwardly of the closed bottom end ofsaid tubular casing, and is detachably and slidably associated with theopen end of said tubular casing in substantially liquid-tight relationin the vicinity of its open top end, and

3) a specimen-pretreating reagent is accommodated in a space betweenouter surface of said cylinder and inner surface of said tubular casing.

A vacuum sampling method according to the fifth aspect of the inventioncomprises

using the vacuum sampling tube according to the first aspect of theinvention and collecting a specimen by vacuum into said inner casing

followed by causing said inner casing to be dissociated from said outercasing, and

adding the specimen in said inner casing to a pretreating reagent insaid outer casing.

A vacuum sampling method according to the sixth aspect of the inventioncomprises

using the vacuum sampling tube according to the second aspect of theinvention and collecting a specimen by vacuum into said cylinder

followed by causing said cylinder and said tubular casing to slideaxially to dissociate the open bottom end of said cylinder from saidplug means,

thereby introducing the specimen in said cylinder into a pretreatingreagent in said tubular casing.

The vacuum sampling method according to the seventh aspect of theinvention comprises

using the vacuum sampling tube according to the third aspect of theinvention and collecting a specimen by vacuum into said cylinder

followed by bringing said cylinder and said tubular casing into relativerotation about the axis to substantially align the notch of the openbottom end of said cylinder with the notch of said plug means,

thereby bringing internal spaces of said cylinder and said casing intocommunication and

introducing the specimen in said cylinder into a pretreating reagent insaid casing.

A vacuum sampling method according to the eighth aspect of the inventioncomprises

using the vacuum sampling tube according to the fourth aspect of theinvention and collecting a specimen by vacuum into said cylinder

followed by pushing said cylinder into said tubular casing to break thebreakable member at the bottom end of said cylinder by the plungermember of said tubular casing,

thereby bringing both internal spaces of said cylinder and said casinginto communication and

introducing the specimen in said cylinder into a pretreating reagent insaid casing.

According to any of the vacuum sampling tubes according to the firstthrough fourth aspects of the invention, since the pretreating reagentwhich would otherwise find its way into the subject's body in the eventof a backflow is accommodated in a vessel independent of the directvessel for a vacuum sampling, the risk in the event of a backflow ofblood or the like during sampling such as blood collecting can beobviated.

According to any of the vacuum sampling methods according to the fifththrough eighth aspects of the invention, since the pretreating reagentwhich would otherwise finds its way into the subject's body in the eventof a backflow is accommodated in a vessel independent of the directvessel for a vacuum sampling, the blending of blood or the like with thepretreating reagent takes place after the vacuum sampling, so that therisk in the event of a backflow of blood or the like during samplingsuch as blood collecting can be obviated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing an example of a vacuum sampling tubeaccording to the first aspect of the invention.

FIG. 2 is a sectional view of the vacuum sampling tube according to thefirst aspect of the invention, with an inner casing and outer casing indissociated positions.

FIG. 3 is a sectional view showing an example of a vacuum sampling tubeaccording to the second aspect of the invention.

FIG. 4 is a sectional view showing the vacuum sampling tube according tothe second aspect of the invention, with a cylinder and tubular casinghaving been axially slid to dissociate the open bottom end of thecylinder from a plug means of the tubular casing.

FIG. 5 is a front view of a vacuum sampling tube according to the thirdaspect of the invention.

FIG. 6 is a longitudinal section view of FIG. 5.

FIG. 7 is a sectional view taken along the line VII—VII of FIG. 5 onmagnified scale.

FIG. 8 is a sectional view showing a vacuum sampling tube according tothe third aspect of the invention, with a notch of the open bottom endof the cylinder aligned with a notch of the plug means.

FIG. 9 is a sectional view showing an example of a vacuum sampling tubeaccording to the fourth aspect of the invention.

FIG. 10 is a sectional view showing the vacuum sampling tube accordingto the fourth aspect of the invention, with a plunger member havingbroken through a breakable gas-barrier member.

FIG. 11 is a sectional view showing another example of the vacuumsampling tube according to the fourth aspect of the invention.

FIG. 12 is a sectional view showing the prior art vacuum bloodcollecting tube.

FIG. 13 is a sectional view showing a vacuum blood collecting needle.

FIG. 14 is a sectional view showing a holder for vacuum bloodcollection.

FIG. 15 is a sketch illustrating the vacuum blood collecting procedureusing the prior art vacuum blood collecting tube.

On the drawings, the reference numerals 1, 11, 21 and 61 each representsa vacuum sampling tube, 2 represents an inner casing, 2 a represents anopen end, 3 represents an outer casing, 3 a represents an open end, 4,14, 24 and 64 each represents a plug, 5, 15, 25 and 65 each represents apretreating reagent, 12 represents a cylinder, 12 a represents an opentop end, 12 b represents an open bottom end, 13 represents a tubularcasing, 13 a represents an open end, 13 b represents a plug means, 22represents a cylinder, 22 a represents an open top end, 22 b representsan open bottom end, 22 c represents a notch, 23 represents a tubularcasing, 23 a represents an open end, 23 b represents a plug means, 23 crepresents a notch, 62 represents a cylinder, 62 a represents an opentop end, 62 b represents an open bottom end, 63 represents a tubularcasing, 63 a represents an open end, 63 b represents a bottomed end, 63c represents a plunger member, 66 represents a gas-barrier member whichcan be broken through at least locally, 66 a represents a breakablepart, 67 represents a cylindrical element, 68 represents a plug element,and 68 a represents a plunger member.

DETAILED DESCRIPTION OF THE INVENTION

An example of a vacuum sampling tube 1 of the first aspect of theinvention is now described, referring to FIG. 1. The vacuum samplingtube 1 is a sampling vessel comprising two tubular casings 2 and 3differing in size and each having a closed bottom and an opening at theother end as assembled together in the manner of a nest of boxes, andcomprises the following structure.

Thus,

1) the inner casing 2 of the nest of boxes is sealed gas-tight at itsopen end 2 a by a gas-barrier, needle hole-sealable plug 4, whereby anegative pressure state is kept within said casing 2,

2) the outer casing 3 of the nest of boxes is substantially not incontact with an outer bottom surface of said inner casing of the nest ofboxes but is detachably associated at the open end 3 a of said outercasing 3 with an outer peripheral surface of said inner casing 2 in thevicinity of its open end 2 a in substantially liquid-tight relation, and

3) a specimen-pretreating reagent 5 is accommodated in a space betweensaid inner casing 2 and said outer casing 3.

The vicinity of the open end 2 a of the inner casing 2 as referred toabove is not necessarily the open end 2 a but may be any locationinsofar as the inner casing 2 and outer casing 3 can be integrated toconstitute a sampling tube 1 with the outer casing 3 held substantiallyliquid-tight before and during sampling.

The invention in its fifth aspect is concerned with a vacuum samplingmethod which comprises using the vacuum sampling tube according to thefirst aspect of the invention and collecting a specimen by vacuum intosaid inner casing 2 by the routine vacuum sampling method followed bycausing said inner casing 2 and said outer casing 3 to be dissociated asillustrated in FIG. 2, removing the plug 4 from said inner casing 2, andadding the specimen in said inner casing 2 to the pretreating reagent insaid outer casing 3. Thereafter, both are blended and, assuming that thespecimen is blood, it maybe fractionated into blood corpuscles, serumand plasma by the routine method and used in various blood examinations.

An example of a vacuum sampling tube 11 of the second aspect of theinvention is now described, referring to FIG. 3. The vacuum samplingtube 11 is a sampling vessel comprising a tubular casing 13 having aclosed bottom and an opening at the other end and a cylinder 12 havingopenings at both ends as assembled in said casing 13 in the manner of anest of boxes, and comprises the following structure. Thus,

1) the open top end 12 a of the inner cylinder 12 of the nest of boxesis sealed gas-tight by a gas-barrier, needle hole-sealable plug 14,

2) said cylinder 12 is detachably associated, respectively, with theopen end 13 a of said tubular casing 13 in the vicinity of its open topend 12 a in substantially liquid-tight relation and with a plug means 13b of said tubular casing 13 in the vicinity of its open bottom end 12 bin substantially gas-tight relation,

3) a negative pressure state is kept within said cylinder 12, and

4) a specimen-pretreating reagent 15 is accommodated in a space betweensaid cylinder 12 and said tubular casing 13.

The plug means 13 b of said tubular casing 13 is formed in such a mannerthat the bottom wall surface of said casing 13 is raised inwardly ofsaid casing l3 to form a hollow cylindrical element (however, the topsurface of said cylindrical element is closed) and the top end thereofis formed so as to be acceptable within the open bottom end 12 b of saidcylinder 12 in gas-tight relation. In this embodiment, said plug means13 b and said tubular casing 13 are provided as a one-piece molding.

The vicinity of the open end 12 a and the vicinity of the open end 12 b,as referred to above, are not necessarily the open end 12 a and open end12 b respectively, but may each be any location insofar as the tubularcasing 13 and cylinder 12 can be integrated to constitute a samplingtube 11 with the cylinder 12 held substantially liquid-tight andgas-tight before and during sampling.

The invention in its sixth aspect is concerned with a vacuum samplingmethod which comprises using the vacuum sampling tube according to thesecond aspect of the invention, and collecting a specimen by vacuum intosaid cylinder 12 by the routine vacuum sampling method followed by, asillustrated in FIG. 4, causing said cylinder 12 and said tubular casing13 to slide axially to dissociate the open bottom end 12 b of saidcylinder 12 from said plug means 13 b, thereby introducing the specimenin said cylinder 12 into the pretreating reagent in said tubular casing13. Thereafter, both are blended and, assuming that the specimen isblood, it may be fractionated into blood corpuscles, serum and plasma bythe routine method and used in various blood examinations.

An example of a vacuum sampling tube 21 of the third aspect of theinvention is now described, referring to FIGS. 5 to 7. FIG. 5 is a frontview of the vacuum sampling tube 21; FIG. 6 is a longitudinal sectionview of the same; and FIG. 7 is a sectional view taken along the lineVII—VII of FIG. 5 on magnified scale. The vacuum sampling tube 21 is asampling vessel comprising a tubular casing 23 having a closed bottomand an opening at the other end and a cylinder 22 having openings atboth ends as assembled in said casing 23 in the manner of a nest ofboxes, and comprises the following structure. Thus,

1) the open top end 22 a of the inner cylinder 22 of the nest of boxesis sealed gas-tight by a gas-barrier, needle-hole sealable plug 24,

2) said cylinder 22 is detachably associated, respectively, with theopen end 23 a of said tubular casing 23 in the vicinity of its open topend 22 a in substantially liquid-tight relation and, with a plug means23 b of said casing 23 in the vicinity of its open bottom end 22 b insubstantially gas-tight relation,

3) said open bottom end 22 b and said plug means 23 bare provided withcomplementary notches 22 c and 23 c and by bringing said cylinder 22into sliding rotation about its axis, the internal spaces of saidcylinder 22 and said casing 23 are reversibly brought into communicationor out of communication,

4) a negative pressure state is kept within said cylinder 22; and

5) a specimen-pretreating reagent 25 is accommodated in a space betweensaid cylinder 22 and said casing 23 surrounding the outside thereof.

The plug means 23 b of said tubular casing 23 is a hollow cylindricalelement erected from the bottom of said tubular casing 23 (the topsurface of said cylindrical element is not closed) and its top end isacceptable with the outer peripheral surface of the open bottom end 22 bof said cylinder 22. In this embodiment, said plug means 23 b and saidtubular casing 23 are provided as a one-piece molding.

The vicinity of the open end 22 a and the vicinity of the open end 22 b,as referred to above, are not necessarily the open end 22 a and the openend 23 b respectively, but may each be any location insofar the tubularcasing 23 and cylinder 22 can be integrated to constitute a samplingtube 21 with the cylinder 22 held substantially liquid-tight andgas-tight before and during sampling.

The seventh aspect of the invention is concerned with a vacuum samplingmethod which comprises using the vacuum sampling tube according to thethird aspect of the invention, and collecting a specimen by vacuum intosaid cylinder 22 by the routine vacuum sampling method followed by, asillustrated in FIG. 8, bringing said cylinder 22 and said tubular casing23 into relative rotation about the axis to substantially align thenotch 22 c of the open bottom end 22 b of said cylinder 22 with thenotch 23 c of said plug means 23 b, thereby bringing internal spaces ofsaid cylinder 22 and said casing 23 into communication and introducingthe specimen in said cylinder 22 into the pretreating reagent in saidcasing 23. Thereafter, both are blended and, assuming that the specimenis blood, it can be fractionated into blood corpuscles, serum and plasmaby the routine method and used in various blood examinations.

An example of a vacuum sampling tube 61 of the fourth aspect of theinvention is now described, referring to FIG. 9. The vacuum samplingtube 61 is a sampling vessel comprising a tubular casing 63 having aclosed bottom and an opening at the other end and a cylinder 62 havingopenings at both ends as assembled in said casing in the manner of anest of boxes, and comprises the following structure. Thus,

1) the open top end 62 a of the inner cylinder 62 of the nest of boxesis sealed gas-tight by a gas-barrier, needle hole-sealable plug 64 whilethe open bottom end 62 b thereof is sealed gas-tight by a gas-barriermember 66 which is in the form of a thin sheet and can be broken throughat least locally, whereby a negative pressure state is kept within saidcylinder 62,

2) said cylinder 62 is designed in such a manner that its open bottomend 62 b faces a projected plunger member 63 c disposed inwardly of theclosed bottom end 63 b of said tubular casing 63, and is detachably andslidably associated with the open end 63 a of said tubular casing 63 insubstantially liquid-tight relation in the vicinity of its open top end62 a, and

3) a specimen-pretreating reagent 65 is accommodated in a space betweensaid cylinder 62 and said tubular casing 63.

In the illustrated embodiment, the gas-barrier member 66 which can bebroken through at least locally is a plug-shaped element having abreakable part 66 a consisting in a thin sheet fitted gas-tight to theopen bottom end of said cylinder 62 but such barrier member 66 may ofcourse be directly bonded or fused to the surface of said open end 62 bby means of a hot-melt type, reaction-curable, or other adhesive or bythe hitherto-known method such as ultrasonic or high-frequency heating.The area and shape of the breakable part 66 a are not particularlyrestricted.

The vicinity of the open end 62 a as referred to above is notnecessarily the open end 62 a but may be any location insofar as thetubular casing 63 and the cylinder 62 can be integrated to constitute asampling tube 61 with the cylinder 62 held substantially liquid-tightbefore and during sampling.

The eighth aspect of the invention is concerned with a vacuum samplingmethod which comprises using the vacuum sampling tube according to thefourth aspect of the invention, and collecting a specimen by vacuum intosaid cylinder 62 by the routine vacuum sampling method followed by, asillustrated in FIG. 10, causing said cylinder 62 and said tubular casing63 to slide axially to break the gas-barrier member 66 which can bebroken through at least locally, thereby introducing the specimen insaid cylinder 62 into the pretreating reagent 65 in said tubular casing63. Thereafter, both are blended and, assuming that the specimen isblood, it can be fractionated into blood corpuscles, serum, and plasmaby the routine method and used in various blood examinations.

In the fourth aspect of the invention, the breakable part 66 a of thegas-barrier member which can be broken through and the plunger member 63c are preferably offset from each other about the axis of said cylinder62 and said tubular casing 63 prior to usage so that a sudden externalforce urging these members toward each other will not unintentionallybring said cylinder 62 into communication with said tubular casing 63.

FIG. 11 is a sectional view showing another example of the vacuumsampling tube 61 according to the fourth aspect of the invention. Inthis embodiment, the breakable part 66 a of the gas-barrier member 66which can be broken through and the plunger member 68 a are offset fromeach other by 180 degrees.

Furthermore, in this embodiment, the tubular casing 63 is formed byfitting an independently molded plug element 68 having a plunger member68 a with a pre-molded cylindrical element 67. In such embodiment, aftercollection of a specimen, said cylinder 62 and said tubular casing 63maybe brought into relative rotation about the A-A′ axis to the locationwhere both of said members can face each other and, then, be pushedagainst each other axially as described above.

In the first through fourth aspects of the present invention, as thematerial of the closed bottom casing and the cylinder having openings atboth ends in the manner of a nest of boxes, for example, various kindsof glass such as hard glass, borosilicate glass, etc.; thermoplasticresins and thermoplastic elastomers obtainable by modification ofsynthetic or natural substances; thermosetting resins and crosslinkableelastomers; and metals can be used each independently or in combination,but transparent or translucent ones are preferred so that one may seethrough the inside.

The casing or cylinder assembled inside in the manner of a nest of boxesis necessary to be kept at a negative pressure state therein in order tocarry out the vacuum sampling. Therefore, it is preferable to usematerials having good gas-barrier properties. Thus, for example, glassand thermoplastic resins such as polyethylene terephthalate,polybutylene terephthalate, polyethylene naphthalate, polyacrylonitrile,polyamide, polyvinyl chloride, inclusive of their derivatives, thecorresponding copolymers with other monomer components, and thecorresponding compositions mixed with various additives are preferablyused each independently or in combination.

As the material which is to constitute the gas-barrier member 66 whichcan be broken through according to the fourth aspect of the invention,the same materials as those mentioned above for the casing or cylinderassembled inside in the manner of the nest of boxes in which a negativepressure state is to be kept can be used. Addition to these,polyvinylidene chloride, ethylene-vinyl alcohol copolymer or an aluminumcan be used each independently or in the form of thin laminate sheetderived therefrom.

In the first through fourth aspects of the invention, the vacuumsampling size can be selected by proper selection of the size of thecasing or cylinder assembled inside in the manner of a nest of boxes andof the degree of decompression, etc.

The casing assembled outside in the manner of a nest of boxes isnecessary to be detachably associated with, according to need, thecasing or cylinder corresponding to the inner box in liquid-tight orgas-tight relation and, therefore, it is preferable to use a flexiblematerial, for example, a thermoplastic resin or thermoplastic elastomerselected from among polyethylene, polypropylene, soft polyvinylchloride, inclusive of their derivatives, the corresponding copolymerswith other monomer components, and the corresponding compositions mixedwith various additives. These may be used each independently or in asuitable combination by laminating, etc. In the case of olefin resinssuch as polyethylene and polypropylene, it is more preferable to useelastic materials obtainable by the copolymerization with an α-olefinmonomer component using the so-called single-site catalyst. Of course,such flexible materials are not exclusive choices but even rigidmaterials can be utilized by inserting or laminating a packing materialmade of an elastic material between the fitting or sliding surface.

In the first through fourth aspects of the invention, as the materialfor the gas-barrier, needle-hole sealable plug to seal the casing orcylinder assembled inside in the manner of a nest of boxes gas-tight,for example, butyl rubber; a composite derived from an aluminum sheetand isoprene rubber or natural rubber; and a thermoplastic elastomer canbe used appropriately.

When the plug is of a dismountable construction, by designing the insidediameter of the open end of the outer casing to be substantially equalto the inside diameter of the plug-accepting part of the casing orcylinder assembled inside in the manner of a nest of boxes, the innercasing or cylinder which is no longer necessary after the collectedspecimen has been blended with the pretreating reagent may be discardedand the plug may then be used as the plug for sealing the opening of theouter casing.

In the second and third aspects of the invention, the plug means of theouter casing which closes the open bottom end of the cylinder assembledinside in the manner of a nest of boxes gas-tight is molded integrallywith the outer casing in the above-mentioned embodiments but it ispossible to mold said plug means independently using butyl rubber or athermoplastic elastomer and install it at the inner bottom surface ofthe outer casing or the inner wall surface of the cylinder in thevicinity of its open bottom end. Furthermore, the outer casing may alsobe molded as a cylindrical element in advance and, then, fitted withsaid pre-molded plug means to constitute the tubular casing.

In the first through fourth aspects of the invention, thespecimen-pretreating reagent is the reagent to be blended with thespecimen. For example, assuming that the specimen is blood, there may bementioned at least one, or a combination, selected from among the knownblood coagulation accelerator, anticoagulant, deproteinizing agent,hemolytic agent, and stabilizer for platelets and the like which aredifficult to be stably maintained due to deactivation, denaturation,metabolism or evaporation, and an assay marker. These can beappropriately accommodated in the form of a solution, a granular powderor a lyophilizate or accommodated by coating on the wall surface or bysupporting on beads, a sheet, a nonwoven fabric or the like.

In the above embodiments, the inner casing or cylinder does not containany drugs that would possibly find its way into the body in the event ofa backflow during sampling but may contain drugs already in use forvarious therapeutic purposes and of which safety has been confirmed, forexample a heparin salt and so forth.

The casing assembled outside in the manner of a nest of boxes and thecasing or cylinder assembled inside in the manner of a nest of boxes,which are to be used in the first to fourth aspects of the invention,can be manufactured by the known production method according to therespective materials to be used therefor. When the above material is athermoplastic resin, for instance, the production method includesinjection molding or blow molding. The vacuum sampling tube according toany of the first to fourth aspects of the invention can be manufacturedby producing the casing assembled outside in the manner of a nest ofboxes and the casing or cylinder assembled inside in the manner of anest of boxes, etc. in the first place and fabricating them.

INDUSTRIAL APPLICABILITY

The conventional vacuum sampling system is available in a broadassortment of sampling tubes containing various pretreating reagents andeach preset to a degree of decompression corresponding to each samplesize. Therefore, taking the collection of blood as an example, all thatis necessary for the person in charge of blood sampling is to pierce theblood vessel accurately with the blood collecting needle and to confirmthat the blood flows in automatically due to the pressure differencebetween the blood vessel and the blood sampling tube. Thus, it is alaudable system contributory to labor saving and standardization ofsampling. The only concern, however, is that the risk of the pretreatingreagent which is contraindicated for injection finding its way into thebody in the event of a backflow cannot be completely ruled out since thebody and the blood collecting tube containing the pretreating reagentare brought into communication even at a short time.

However, with the vacuum sampling tube and in accordance with the vacuumsampling method of the invention, the space accommodating a specimen iscompletely isolated from the space accommodating the pretreating reagentat the time of vacuum sampling so that the risk of the pretreatingreagent finding its way into the body in the event of a backflow iscompletely nil. It is, therefore, expected that the invention willexpedite the spread of use of this sampling system with added safety.

In some examinations, it is necessary to follow up the time course ofchange in the reaction product resulting from the blending of thespecimen with the pretreating reagent. In such cases, if the blendingwith the pretreating reagent begins immediately upon inflow of thespecimen as it is the case with the prior art and if it takes much timebefore completion of blood collecting unexpectedly due to troubles suchthat the blood collecting needle does not remain properly secured inposition because of the fineness of the subject's blood vessel or thesubject's blood pressure drops during blood collecting, the reactionstart time is obscured so that the proper monitor cannot be achieved. Inthis respect, as in the present invention, when the space accommodatinga specimen is isolated from the space accommodating the pretreatingreagent, both can be blended at one time immediately before carrying outan examination so that it is extremely useful to improve the accuracy ofexaminations.

What is claimed is:
 1. A vacuum sampling tube which is a sampling vesselconsisting of two tubular casings differing in size and each having aclosed bottom and an opening at the other end as assembled together inthe manner of a nest of boxes, in which 1) the inner casing of the nestof boxes is sealed gas-tight at its open end by a gas-barrier, needlehole-sealable plug, whereby a negative pressure state is kept withinsaid casing, 2) the outer casing of the nest of boxes does not have aplug, and is substantially not in contact with an outer bottom surfaceof said inner casing of the nest of boxes but is detachably associatedat the open end of said outer casing with an outer peripheral surface ofsaid inner casing in the vicinity of its open end in substantiallyliquid-tight relation, and 3) a specimen-pretreating reagent isaccommodated in a space between said inner casing and said outer casing.2. A vacuum sampling tube which is a sampling vessel consisting of atubular casing having a closed bottom and an opening at the other endand a cylinder having openings at both ends as assembled in said casingin the manner of a nest of boxes, in which 1) the open top end of theinner cylinder of the nest of boxes is sealed gas-tight by agas-barrier, needle hole-sealable plug, 2) said cylinder is detachablyassociated, respectively, with the open end of said tubular casing inthe vicinity of its open top end in substantially liquid-tight relationand with a plug means of said tubular casing in the vicinity of its openbottom end in substantially gas-tight relation, 3) a negative pressurestate is kept within said cylinder, and 4) a specimen-pretreatingreagent is accommodated in the space between said cylinder and saidtubular casing, and 5) said tubular casing does not have a plug.
 3. Avacuum sampling tube which is a sampling vessel consisting of a tubularcasing having a closed bottom and an opening at the other end and acylinder having openings at both ends as assembled in said casing in themanner of a nest of boxes, in which 1) the open top end of the innercylinder of the nest of boxes is sealed gas-tight by a gas-barrier,needle hole-sealable plug, 2) said cylinder is detachably associated,respectively, with the open end of said tubular casing in the vicinityof its open top end in substantially liquid-tight relation and with aplug means of said tubular casing in the vicinity of its open bottom endin substantially gas-tight relation, 3) said open bottom end and saidplug means are provided with complementary notches and by bringing saidcylinder into sliding rotation about its axis, internal spaces of saidcylinder and said casing are reversibly brought into communication orout of communication, 4) a negative pressure state is kept within saidcylinder, and 5) a specimen-pretreating reagent is accommodated in aspace between said cylinder and said casing surrounding the outsidethereof, and 6) said tubular casing does not have a plug.
 4. A vacuumsampling tube which is a sampling vessel consisting of a tubular casinghaving a closed bottom and an opening at the other end and a cylinderhaving openings at both ends as assembled in said casing in the mannerof a nest of boxes, in which 1) the open top end of the inner cylinderof the nest of boxes is sealed gas-tight by a gas-barrier, needlehole-sealable plug while the open bottom end thereof is sealed gas-tightby a gas-barrier member which may be broken through at least locally,whereby a negative pressure state is kept within said cylinder, 2) saidcylinder is designed in such manner that its open bottom end faces aplunger member disposed inwardly of the closed bottom end of saidtubular casing and, is detachably and slidably associated with the openend of said tubular casing in substantially liquid-tight relation in thevicinity of its open top end, and 3) a specimen-pretreating reagent isaccommodated in a space between said cylinder and said tubular casing,and said tubular casing does not have a plug.
 5. A vacuum samplingmethod which comprises using the vacuum sampling tube according to claim1 and collecting a specimen by vacuum into said inner casing followed bycausing said inner casing to be dissociated from said outer casing, andadding the specimen in said inner casing to a pretreating reagent insaid outer casing.
 6. A vacuum sampling method which comprises using thevacuum sampling tube according to claim 2 and collecting a specimen byvacuum into said cylinder followed by causing said cylinder and saidtubular casing to slide axially to dissociate the open bottom end ofsaid cylinder from said plug means, thereby introducing the specimen insaid cylinder into a pretreating reagent in said tubular casing.
 7. Avacuum sampling method which comprises using the vacuum sampling tubeaccording to claim 3 and collecting a specimen by vacuum into thecylinder followed by bringing said cylinder and said tubular casing intorelative rotation about the axis to substantially align the notch of theopen bottom end of said cylinder with the notch of said plug means,thereby bringing internal spaces of said cylinder and said casing intocommunication and introducing the specimen in said cylinder into apretreating reagent in said casing.
 8. A vacuum sampling method whichcomprises using the vacuum sampling tube according to claim 4 andcollecting a specimen by vacuum into said cylinder followed by pushingsaid cylinder into said tubular casing to break the breakable member atthe bottom end of said cylinder by the plunger member of said tubularcasing, thereby bringing both internal spaces of said cylinder and saidcasing into communication and introducing the specimen in said cylinderinto a pretreating reagent in said casing.